Pump assembly for pumping a fluid lubricant

ABSTRACT

A pump assembly for pumping a fluid lubricant such as grease or oil, the pump assembly comprising: a pump mechanism configured for moving a fluid lubricant; a pneumatic cylinder configured for being powered by an air source, the pneumatic cylinder comprising: a movable member for operating the pump mechanism, wherein the pump assembly further comprises a switch for detecting a position of the movable member; a valve configured for shifting a position of the moveable member upon an activation of the valve; and a control unit operable connected to the switch and the valve. The control unit is configured for controlling the activation of the valve in response to a detection of the position of the movable member by the switch, such that a pumping effect of the pump mechanism can be controlled. The pump assembly can be integrated into a lubrication system.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a United States National Stage Application claiming the benefit of International Application Number PCT/EP2014/000440 filed on 18 Feb. 2014 (Feb. 18, 2014), which claims the benefit of Sweden (SE) Patent Application Number 1300127-6 filed on 19 Feb. 2013 (Feb. 19, 2013) both of which are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention pertains to a pump assembly for pumping a fluid lubricant such as grease or oil in a lubrication system. Additionally, the present invention pertains to a lubrication system including a pump assembly for pumping a fluid lubricant such as grease or oil.

BACKGROUND OF THE INVENTION

In lubrication systems for bearings, there is a need for feeding oil or grease to the bearing in order to ensure that there is sufficient amount of lubricant in the bearing. In addition, there is also a need for transporting the oil or grease from a reservoir, tank or dispenser to a pipe of the lubrication system or the pipe of a feeding pump. Oil and grease are commonly used as fluid lubricants in bearings.

Various types of pump mechanisms are known for use in lubrication system. As an example, a barrel pump can be used for transporting the fluid lubricant, e.g. oil or grease, from the reservoir to the pipe of the lubrication system. Besides transporting the fluid lubricant to a bearing, the pump assembly can also be used when the bearing or bearing house is re-filled with fluid lubricant. Hence, the pump assembly can either be used as a feeding pump or a transfer pump.

Typically, the lubrication system is provided with an external valve for controlling the amount of lubrication so as to ensure that a correct quantity of lubricant is injected at the right intervals. Over-greasing can have detrimental effects on the life of a bearing and will contribute to machine downtime and early failure. However, this type of lubrication system is based on mechanical dosing and do only account for static adjustment in the sense that they can only provide a fixed amount of fluid lubricant at a predetermined time interval. For this reason, there remains a need in the field of lubrication system for improving and controlling the lubrication of a bearing. In a more general formulation of the problem, there is a need for improving the feeding and pumping of a fluid lubricant such as oil or grease.

SUMMARY OF THE INVENTION

In the light of the above, it is the object underlying the present invention to provide a pump assembly in which a pumping effect can be controlled in an improved manner.

In accordance with a first aspect of the present invention, a pump assembly for pumping a fluid lubricant such as grease or oil, the pump assembly comprising:

-   -   a pump mechanism having a fluid lubricant inflow line and a         fluid lubricant outflow line, wherein the pump mechanism is         configured for moving a fluid lubricant;     -   a pneumatic cylinder having an air inlet and an air outlet,         wherein the pneumatic cylinder is configured for being powered         by an air source, the pneumatic cylinder comprising a movable         member for operating the pump mechanism, the movable member is         movable from an upper position to a lower position in an axial         direction;     -   a switch for detecting a position of the movable member;     -   a valve configured for shifting a position of the moveable         member upon an activation of the valve; and     -   a control unit operably connected to the switch and the valve,         wherein the control unit is configured for controlling the         activation of the valve in response to a detection of the         position of the movable member by the switch, such that a         pumping effect of the pump mechanism can be controlled.

In accordance with a second aspect of the present invention, the pumping effect of the pump mechanism is controlled according to a stroke control mode.

In accordance with another aspect of the present invention, the pumping effect of the pump mechanism is controlled according to a time delay mode.

In accordance with yet another aspect of the present invention, the control unit is capable of delaying the activation of the valve in response to a detection of the position of the movable member by the switch such that the pumping effect of the pump mechanism is time delayed.

In accordance with yet another aspect of the present invention, the activation of the valve is delayed by maintaining the movable member at least one of in an upper position and in a lower position.

In accordance with yet another aspect of the present invention, the control unit is configured for controlling the activation of the valve in response to external control information.

In accordance with yet another aspect of the present invention, the control unit is configured to record various pumping parameters.

In accordance with yet another aspect of the present invention, the pumping parameters can include at least one of: flow rate information, dosage amount information and suction level setting.

In accordance with yet another aspect of the present invention, the movable member is operable connected to a pumping shaft of the pump mechanism.

In accordance with yet another aspect of the present invention, the pump assembly further comprises a sensor for detecting a flow rate.

In accordance with yet another aspect of the present invention, the pump assembly further comprises a sensor for detecting a dosage amount.

In accordance with yet another aspect of the present invention, the pneumatic cylinder further comprises a first air chamber and a second air chamber.

In accordance with yet another aspect of the present invention, the pump mechanism is provided with a suction side and a pressure side, the suction side is connected to the pressure side via a bypass channel.

In accordance with yet another aspect of the present invention, the pump mechanism is provided in the form of a barrel pump.

In accordance with yet another aspect of the present invention, the pump mechanism is integrated into a lubrication system.

In accordance with yet another aspect of the present invention, the pump mechanism is integrated into a lubrication system, the lubrication system further comprises a dispenser, wherein the dispenser is operably connected to the pump assembly.

Hence, according to a first aspect of the present invention there is provided a pump assembly for pumping a fluid lubricant such as grease or oil. The pump assembly comprises a pump mechanism which has a fluid lubricant inflow line and a fluid lubricant outflow line. The pump mechanism is configured for moving the fluid lubricant. The pump assembly further includes a pneumatic cylinder which has an air inlet and an air outlet, and configured for being powered by an air source. The pneumatic cylinder comprises a movable member for operating the pump mechanism. The movable member is movable from an upper position to a lower position in an axial direction A. Moreover, the pump assembly comprises a switch for detecting a position of the movable member. The pump assembly further includes a valve configured for shifting a position of the moveable member upon an activation of the valve. In addition, the pump assembly includes a control unit operable connected to the switch and the valve, whereby the control unit is configured for controlling the activation of the valve in response to a detection of the position of the movable member by the switch such that a pumping effect of the pump mechanism can be controlled.

By the principle of the present invention, it becomes possible to control the pumping effect of the pump mechanism allowing fluid lubricant to be dispatched in an effective and improved manner. In particular, the present invention provides a pump assembly which is capable of either controlling the flow rate of a fluid lubricant or the dosage amount of the fluid lubricant in a lubrication system. Alternatively, the pump assembly can be configured such that both the flow rate of the fluid lubricant and the dosage amount of the fluid lubricant in a lubrication system are controlled. The term pumping effect may refer to pumping according to time delays, i.e. time delay mode, and/or pumping according to a predetermined dosage amount, i.e. stroke control mode. Time delay mode and stroke control mode are described in greater detail herein below.

In contrast to available prior art pump assemblies, which require mechanical control by means of an external valve arranged between the air source and the pump, the present invention provides a pump assembly including a control unit such that the pump mechanism of the pump assembly can be directly controlled by the integrated control unit. Conventionally, the control has been performed by mechanically controlling the air flow from the air source to the pump, i.e. operating the external valve according to various predetermined conditions such as the temperature of the lubricant, viscosity of the lubricant, air pressure or air flow. In contrast to available prior art pump assemblies, which require mechanical control by means of an external valve arranged between the air source and the pump, the present invention provides a pump assembly including a control unit such that the pump mechanism of the pump assembly can be directly controlled by the integrated control unit.

The present invention is particular suitable for pumping high viscosity lubricant. High viscosity refers to a viscosity above 10 000 cSt in +40° C. and up to 90 000 cSt in +40° C. High viscosity lubricant is extremely problematic to pump or transport in conventional lubricant system using a conventional pump assembly since such pump assemblies are often improperly controlled which results in a shortage of fluid lubricant in the pump assembly. Accordingly, by the present invention, it becomes possible to control the pumping effect of the pump mechanism such that the speed of the pump is limited allowing a sufficient amount of fluid lubricant to flow to the suction area of the pump mechanism. Moreover, by the provision that the pumping effect of the pump mechanism can be controlled, the pump assembly is configured such that no over-greasing is carried out.

In addition, the present invention provides a compact and economical pump assembly in the sense that the pumping effect can be controlled so as to provide fluid lubricant only when it is required by the lubrication system.

The function of the movable member is to move the pump mechanism. The movable member is movable from the upper position to the lower position when air pressure is applied to the pneumatic cylinder. Analogously, the movable member is movable from the lower position to the upper position when air pressure is exhausted from the pneumatic cylinder. In this manner, the movable member is capable of moving the pump mechanism according to a predetermined manner such that fluid lubrication can be transported in a lubrication system.

As mentioned above, the pump assembly is preferably connected to an external air source, such as an air pump or the like. In this manner, the pneumatic cylinder is pressurized by the external air source.

In one preferred embodiment of the present invention, the pumping effect of the pump mechanism is controlled according to a stroke control mode. In the context of the present invention, the term stroke control mode here refers to a control of the dosage amount of the fluid lubrication. By controlling the dosage amount of the fluid lubrication, it becomes possible to provide a certain amount of fluid lubricant at a certain time. Accordingly, the present invention provides a technical solution which is effective and economic in the sense that pumping of fluid lubricant is only activated when it is required by the lubrication system and/or the bearing.

In the context of the present invention, the term suction stroke refers to a movement of the movable member from an upper position to a lower position. The term work stroke refers to a movement of the movable member from a lower position to an upper position. Hence, one pulse is defined by a suction stroke and a work stroke. By controlling the pump effect according to stroke control mode, the user of the pump assembly is capable of specifying the amount of the lubricant to the lubrication system. This is particularly suitable in situations when less fluid lubricant is required compared to the conventional situation. For example, many lubrication systems require less oil in the summer than in the winter. Hence, the pump effect of the pump mechanism according to the present invention can be controlled according to stroke control mode such that no excessive amount of lubricant is supplied.

In another preferred embodiment of the present invention, the pumping effect of the pump mechanism is controlled according to a time delay mode. In this context, the control unit is adapted to control the time interval of one pulse of the moveable member. By this principle, it becomes possible to maintain the movable member (piston) in its lower position. Typically, when the movable member is in its lower position, the pump mechanism is in its open state allowing fluid lubrication to be sucked up. Accordingly, in this context of the present invention, the lower position of the movable member corresponds to an open state of the pump mechanism. The advantage of maintaining the movable member in its lower state is that the time period for suction of fluid lubricant by the pump mechanism is extended. This is particularly important for high viscosity lubricant. Hitherto known pump assemblies are not capable of maintaining the movable member (piston) in its lower position, making them less suitable for high viscosity lubricant. In other words, by controlling the pumping effect according to time delay mode, it becomes possible to control the suction of the pump mechanism, i.e. the pumping effect.

The control unit may include a microprocessor, microcontroller, programmable digital signal processor or another programmable device. The control unit may also, or instead, include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. Where the control unit includes a programmable device such as the microprocessor, microcontroller or programmable digital signal processor mentioned above, the processor may further include computer executable code that controls operation of the programmable device.

Preferably, the control unit is capable of delaying the activation of the valve in response to a detection of the position of the movable member by the switch such that the pumping effect of the pump mechanism is time delayed. In this manner, it becomes possible to maintain the movable member in the upper position and/or in the lower position, allowing the pump mechanism to be filled with a sufficient amount of lubricant. This configuration is particularly important for high viscosity lubricants. As such, the present invention provides a pump assembly which is capable of being filled with a maximum amount of fluid lubricant.

Preferably, the activation of the valve is delayed by maintaining the movable member in an upper position. Alternatively, the activation of the valve is delayed by maintaining the movable member in a lower position.

Valves are commonly known in the art; hence, a suitable valve for the pump assembly can be selected by the skilled person depending on the specific situation. As an example, the valve can be provided in the form of a solenoid valve.

Preferably, the switch is provided in the form of a proximity switch. However, other types of switches are conceivable as long as the switch is capable of detecting a position of the movable member. By detecting the position of the movable member, it becomes possible to control the dosage amount of the pump mechanism. For instance, if the stroke volume is set to 5.5 gram/stroke, the dosage amount is controlled according to the principle above, i.e. by controlling the movement of the pump mechanism, such that the pump assembly can determine when this stroke volume should be delivered to the lubrication system.

Advantageously, the control unit is configured for controlling the activation of the valve in response to external control information. External information can be provided to the control unit in the form of electric flow rate control information, dosage amount information etc.

Advantageously, the control unit is configured to record various pumping parameters such as flow rate information, dosage amount information and/or suction level setting(s).

Preferably, the movable member is provided in the form of a piston. However, the movable member may also be provided in the form of a plunger or membrane. In various exemplifying embodiments, the movable member may be operable connected to a pumping shaft of the pump mechanism. The pumping shaft may be a separate part of the pump mechanism. Alternatively, the pumping shaft may be an integral part of the pump mechanism.

In various exemplifying embodiments, the pump assembly may further comprise a sensor for detecting a flow rate. Alternatively, or in addition, the pump assembly may further comprise a sensor for detecting a dosage amount. Sensors are commonly know in the art, and the selection of a suitable sensor is ultimately dependent on the desired measurements to be carried out and the use and installation of the pump assembly. In addition, or alternatively, the sensors can be used to monitor the amount of lubricant dispensed through the pump mechanism, and compare it with the predetermined amount of lubricant. In this manner, it becomes possible to confirm the operation of the pump assembly, or calibrate, without any interruptions during lubrication.

Preferably, the pump mechanism is provided in the form of a barrel pump. A barrel pump typically has a suction side and a pressure side. The suction side is connected to the pressure side via a bypass channel.

In one preferred embodiment, the pneumatic cylinder comprising a first air chamber and a second air chamber.

According to a second aspect of the present invention there is provided a lubrication system including a pump assembly according to any of the aspects above and embodiments thereof. Preferably, the lubrication system further comprises a dispenser. In this context, the dispenser is operable connected to the pump assembly.

There are several types of lubrications system. For instance, the pump assembly can be used in a single-line lubrication system. Alternatively, the pump assembly can be implemented in a dual-line lubrication system. Alternatively, the pump assembly can be used in a progressive lubrication system.

Applications of lubrication systems include heavy industry, metal working plants, pulp and paper, mining, mineral processing and cement factories, deck cranes, power plants and more.

Preferably, the lubrication system may include a distributor configured to feed a quantity of fluid lubricant to a lubrication point.

Additional effects and features of this second aspect of the present invention are largely analogous to those described above in connection with the first aspect of the invention.

In various exemplifying embodiments, the lubrication system may further comprise a sensor for detecting a flow rate. Alternatively, or in addition, the lubrication system may further comprise a sensor for detecting a dosage amount.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled addressee realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 schematically illustrates an exploded view of an example of a pump assembly according to the invention, which pump assembly comprises a control unit;

FIG. 2 schematically illustrates a cross-sectional view of an example of a pump assembly according to the invention, which pump assembly comprises a control unit;

FIG. 3 a schematically illustrates an example of a single-line lubrication system according to the present invention;

FIG. 3 b schematically illustrates an example of a dual-line lubrication system according to the present invention;

FIG. 3 c schematically illustrates an example of a progressive lubrication system according to the present invention.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout. Note that the directions in the following description are used for facilitating the understanding of a positional relation between components in the figures. Therefore, the installation direction, use mode, and the like of the bearing assembly are not specified thereby. The same is applied to other embodiments described below.

Although the following description has been made to a conventional barrel pump, the present invention may as well be implemented in other similar pump mechanisms.

Referring now to the drawings and to FIGS. 1 and 2 in particular, there is depicted an example of a pump assembly according to the present invention. The pump assembly 100 is configured for pumping a fluid lubricant 220 such as grease or oil.

The pump assembly pump may be particularly, but not exclusively, used for lubrication system such as a single-line lubrication system 300, dual-line system lubrication system 400 or progressive system lubrication system 500, as illustrated in FIGS. 3 a-3 c. The installation of the pump assembly 100 in a lubrication system is further described below.

In the illustrated embodiment as shown in FIGS. 1 and 2, the pump assembly includes a pump mechanism 120. The pump mechanism 120 has a fluid lubricant inflow line 124 and a fluid lubricant outflow line 128. The pump mechanism 120 is configured for moving the fluid lubricant 220. Accordingly, during a pumping cycle, the pump mechanism 120 contains a fluid lubricant 220 of a suitable viscosity.

Typically, the pump mechanism 120 is provided in the form of a barrel pump. Barrel pumps are commonly known in the art. Typically, the pump mechanism (or barrel pump) 120 includes a pump housing 180 (not shown). A barrel pump is designed to transport or dispense the fluid lubricant. The components of the barrel pump can be made of a wide range of materials, including PVDF, PP, stainless steel. A barrel pump can work with different pressures and has a variable head depending on air pressure and fluid lubricant viscosity. Typically, a barrel pump is operated on a centrifugal pumping principle or a progressive cavity (screw) pumping principle. The pump mechanism 120 may include further components. For instance, the pump mechanism 120 may include an adapter (not shown). The adapter may be a separate component or may be integrated into a locking hub. The adapter aligns and offsets a dispenser's axis parallel to the longitudinal axis of the pump mechanism 120 such that a plunger rod of the pump mechanism 120, when rotated, mates with a drive screw of the pump mechanism 120. The barrel pump may also contain a locking tab to prevent rotation of the barrel pump with respect to the pump assembly and/or dispenser.

Since the functions of the components of the barrel pump are apparent to the skilled person, the pump mechanism is not further described herein.

The pump assembly 100 further includes a pneumatic cylinder 160 which has an air inlet 164 and an air outlet 168. The pneumatic cylinder 160 is here configured for being powered by an air source 200 (not shown). Accordingly, the pump assembly is preferably operable connected to the external air source, e.g. an air pump or the like such that the pneumatic cylinder 160 is pressurized by the external air source.

The pneumatic cylinder 160 is provided with a movable member 130 for operating the pump mechanism 120. As is illustrated in FIG. 1, the movable member 130 is movable from an upper position 134 to a lower position 136 in an axial direction A. In a preferred embodiment, the movable member 130 is provided in the form of a piston. As illustrated in FIGS. 1 and 2, the movable member 130 is co-axially arranged within the pneumatic cylinder 160. The pneumatic cylinder 160 thereby surrounds a major part of the movable member 130.

The inner volume of the pneumatic cylinder 160 may be defined or formed by a first air chamber 250 and a second air chamber 260, as shown in FIGS. 1 and 2. However, the inner volume of the pneumatic cylinder 160 may also constitute one inner volume which is separated into two sub-volumes by the movable member 130. As is evident from the schematic view of the pump assembly 100 in FIGS. 1 and 2, it is noted that the volume of the first air chamber 250 and the volume of the second air chamber 260 are determined by the position of the movable member 130. Accordingly, by a movement of the moveable position 130 from the lower position 136 to the upper position 134, it is realised that the volume of the first air chamber 250 is decreased while the volume of the second air chamber 260 is increased. Analogously, by a movement of the moveable position 130 from the upper position 134 to the lower position 136, it is realised that the volume of the first air chamber 250 is increased while the volume of the second air chamber 260 is decreased.

In order to detect a position of the movable member 130, the pump assembly 100 further includes a switch 140. That is, the switch 140 is adapted for detecting a position of the movable member 130.

As illustrated in FIGS. 1 and 2, the pump assembly 100 includes a valve 150 configured for shifting a position of the moveable member 130 upon an activation of the valve 150. By the phrase shifting a position is meant that the valve 150 is capable of changing the direction of the movable member 130 from the upper position 134 to the lower position 136. Analogously, the valve 150 is also capable of changing the direction of the movable member 130 from the lower position 136 to the upper position 134. In a preferred embodiment, the valve 150 is provided in the form of a solenoid valve.

As illustrated in FIGS. 1 and 2, the movable member 130 here is operable connected to a pumping shaft 240 of the pump mechanism 120. In this manner, the pump mechanism can be activated by the movable member 130, such that a change in the position of the movable member 130 results in a change of the position of the pump mechanism 120. For instance, a change in position of the movable member 130 from the lower position 136 to the upper position 134 may correspond to a certain predetermined movement of the pumping shaft 240 such that the pump mechanism 120 is activated in a desired manner. The ultimate functional relationship between the movable member 130, the pumping shaft 240 and the pump mechanism 120 is dependent on the use and installation of the pump assembly 100. Accordingly, various functional relationships between these components are conceivable and any adjustment of the functional relationship will be apparent to the skilled person in the art.

In order to control the activation of the valve 130, the pump assembly 100 includes a control unit 110 operable connected to the switch 140 and the valve 150. The control unit 110 is configured for controlling the activation of the valve 150 in response to a detection of the position of the movable member 130 by the switch 140, such that a pumping effect of the pump mechanism 120 can be controlled.

In one preferred embodiment of the present invention, the pumping effect of the pump mechanism 120 is controlled according to a stroke control mode. In the context of the present invention, the term stroke control mode here refers to a control of the dosage amount of fluid lubricant 220. As an example, the pumping effect can be controlled such that the pump mechanism 120 supplies an amount of 5.5 g of grease per pulse. One pulse is defined by a suction stroke and a work stroke. If the pump mechanism completes one pulse per minute, the total amount of fluid lubricant per minute is 5.5 g/min.

Thereby, the pump assembly is capable of pumping 55 g dosage by making ten pulses. The flow rate can be set by the control unit to supply e.g. 60 g/min or 200 g/min. Other alternatives are conceivable and will be apparent to the skilled person dependent on the installation and use of the pump assembly.

In the context of the present invention, the term suction stroke refers to a movement of the movable member from an upper position to a lower position. The term work stroke refers to a movement of the movable member from a lower position to an upper position. Hence, by controlling the pump effect according to stroke control mode, the user of the pump assembly is capable of specifying the amount of the lubricant to the lubrication system.

In another preferred embodiment of the present invention, the pumping effect of the pump mechanism 120 is controlled according to a time delay mode. In this context, the control unit 110 is adapted to control the time interval of one pulse of the moveable member 130. As an example, the time delay mode can be set to a time delay of 0.3 s. In another example, the time delay mode can be set to a time delay of 0.6 s. However, various time delay modes are conceivable, and the ultimate selection of a suitable time delay mode will be apparent to the skilled person dependent on the installation and use of the pump assembly.

The control unit may include a microprocessor, microcontroller, programmable digital signal processor or another programmable device. The control unit may also, or instead, include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. Where the control unit includes a programmable device such as the microprocessor, microcontroller or programmable digital signal processor mentioned above, the processor may further include computer executable code that controls operation of the programmable device.

The control unit 110 is capable of delaying the activation of the valve 150 in response to a detection of the position of the movable member 130 by the switch 140 such that the pumping effect of the pump mechanism 120 is time delayed.

The activation of the valve 150 is delayed by maintaining the movable member 130 in the upper position 134 and/or in the lower position 136.

In all embodiments of the present invention, the control unit 110 can be configured for controlling the activation of the valve 150 in response to external control information. External information can be provided to the control unit 110 in the form of electric flow rate control information, dosage amount information etc.

Moreover, in all embodiments of the present invention, the control unit 110 can be configured to record various pumping parameters such as flow rate information, dosage amount information and/or suction level setting(s).

In various exemplifying embodiments, the pump assembly 100 may further comprise a sensor 270 (not shown) for detecting a flow rate. Alternatively, or in addition, the pump assembly 100 may further comprise a sensor 280 (not shown) for detecting a dosage amount.

If compared with, for example, known barrel pumps or pump assemblies, the present solution provides the advantages that the pump assembly is capable of either controlling the flow rate of a fluid lubricant and/or the dosage amount of the fluid lubricant in a lubrication system. This is possible by controlling the pumping effect of the pump mechanism allowing fluid lubricant to be dispatched in an effective and improved manner. In contrast to available prior art pump assemblies, which require mechanical control by means of an external valve arranged between the air source and the pump, the present invention provides a pump assembly including a control unit such that the pump mechanism of the pump assembly can be directly controlled by the integrated control unit.

Thanks to the configuration provided by the components of the pump assembly, the present invention provides a compact and economical pump assembly in the sense that the pumping effect can be controlled so as to provide fluid lubricant only when it is required by the lubrication system. Hence, by means of the pump assembly according to the present invention, over-greasing is avoided or at least reduced. Over-greasing can have detrimental effects on the life of a bearing and will contribute to machine downtime and early failure.

As mentioned above, the term pumping effect may refer to pumping according to time delays, i.e. time delay mode, and/or pumping according to a predetermined dosage amount, i.e. stroke control mode. Time delay mode and stroke control mode are described in greater detail herein below.

As illustrated in FIG. 1, the pump assembly 100 here is provided with a cover 170. The cover 170 is designed to protect the components of the pump assembly 100.

As mentioned above, the pump assembly 100 suitable for pumping a fluid lubricant 220 within a lubrication system 300, 400 and 500. Hence, as illustrated in FIGS. 3 a-3 c, there is provided a lubrication system including a pump assembly 100 according to any of the aspects above and embodiments thereof. Applications of lubrication systems include heavy industry, metal working plants, pulp and paper, mining, mineral processing and cement factories, deck cranes, power plants and more.

Turning now to FIGS. 3 a-3 c, the lubrication system 300, 400 and 500 here comprises a dispenser 390. In this context, the dispenser 390 is operable connected to the pump assembly 100. The dispenser 390 contains the fluid lubricant 220 for delivery to a bearing and is of variable interior volume.

There are several types of lubrications system. For instance, the pump assembly 100 can be used in a single-line lubrication system 300, as shown in FIG. 3 a. Alternatively, the pump assembly 100 can be implemented in a dual-line lubrication system 400, as is shown in FIG. 3 b. Alternatively, the pump assembly 100 can be used in a progressive lubrication system 500, as is shown in FIG. 3 c.

FIG. 3 a schematically illustrates an example of a single-line lubrication system 300 according to the present invention. In a single-line system 300, there is only one lubricant point 350 assigned to each lubricant outlet 370. In this system, there may also be lubrication distributors 360 configured to feed a quantity of fluid lubricant 220 to the lubrication point 350 during the pressure build-up in the main line 380 i.e. while the pump assembly 100 is running. The pump assembly 100 is configured to feed the fluid lubricant 220 via the main line 380 to the lubricant distributors 360, where it is metered and fed to the lubrication points 350. Depending on the type of distributors used, this is performed during or after the pump cycle. The individual lubricant requirement for each lubrication point 350 can be adapted using different metering nipples (not shown).

In addition, or alternatively, the system may also be provided with re-lubrication distributors (not shown). Re-lubrication distributors do not feed the lubricant to the lubrication point until the pressure relief process in the main line has been completed, i.e. after the pump assembly (100) has been turned off. Re-lubrication distributors are configured to work like spring-energy accumulators. If, for example, lubrication points are subject to heavy loads during the lubricating cycle, the lubricant is stored in the distributor and not discharged until the friction points move or are relieved of pressure.

FIG. 3 b schematically illustrates an example of a dual-line lubrication system 400 according to the present invention. A dual-line lubrication system 400 is designed with two simultaneous main lines 410, 420. One of the main lines 410 or 420 is pressurized while the other is relieved of pressure. In order to perform a complete lubrication cycle, both main lines 410, 420 have to be alternately pressurized and relieved of pressure. As such, the system 400 requires two main lines 410, 420 that are alternately supplied with fluid lubricant 220. As for the single-line system, the dual-line lubrication system 400 may include one or several distributors 360. The distributors 360 are typically configured to measure an adjustable quantity of fluid lubricant per lubrication cycle. Moreover, in a dual-line lubrication system 400, each lubrication point 350 typically has its own distributor outlet. A dual-line distributor 360 can serve even or odd number of lubrication points 350. A dual-line lubrication system offers great flexibility when it comes to adjusting the metered quantity to the requirements of a specific lubrication point 350.

FIG. 3 c schematically illustrates an example of a progressive lubrication system 500 according to the present invention. In contrast to single-line lubrication system and dual-line lubrication system, a progressive lubrication system 500 distributes fluid lubricant progressively to a bearing assembly. In this type of system, the pump assembly 100, supplies fluid lubricant 220 through the main line 380 to the distributor 360 which serves each outlet progressively, with a defined amount of fluid lubricant. To control the function of the progressive lubrication system, only one progressive feeder 510 has to be controlled on a frequency basis. The advantage of the system 500 is that it can serve up to 150 lubrication points 350 with grease or oil.

A progressive feeder 510 distributes the fluid lubricant 220 it receives during the contact time to the lubrication points 350 one after another in amounts relative to the individual metering rates of each section. Each feeder outlet 370 can only supply one lubrication point 350 with fluid lubricant 220. However, if the demand for fluid lubricant is high at one lubrication point 350, several outlet ports 370 can be combined into one. Thanks to the way a feeder 510 works, it is possible to monitor its operation by way of a piston stroke indicator (visual) or a piston detector (electrical or electronic). The system 500 can be configured according to various conditions such as the operating conditions, installation conditions, commercial requirements, technical demands on the metering volume of each outlet port etc.

By means of the installation of the pump assembly into a lubrication system, the amount of lubricant fed to a lubrication point can be controlled by the pump assembly. In this manner, it becomes possible to control the total amount of fluid lubricant that is fed to the lubrication system. By controlling the total amount of fluid lubricant, it becomes possible to detect possible leakages in dividers/distributors or piping

Note that in all the embodiments of FIGS. 3 a through 3 c, the pump assembly 100 typically is connected to the dispenser 390, and configured to dispense fluid lubricant 220 from the dispenser 390 to various lubrication points 350.

In various exemplifying embodiments, the lubrication system 300, 400 and 500 may further comprise a sensor 270 (not shown) for detecting a flow rate. Alternatively, or in addition, the lubrication system 300, 400 and 500 may further comprise a sensor 280 (not shown) for detecting a dosage amount.

Additionally, even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. Variations to the disclosed embodiments can be understood and effected by the skilled addressee in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Furthermore, in the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality.

REFERENCE NUMERALS

-   100 pump assembly -   110 control unit -   120 pump mechanism -   124 pump mechanism fluid lubricant inflow line -   128 pump mechanism fluid lubricant outflow line -   130 movable member -   140 switch -   150 valve -   160 pneumatic cylinder -   164 pneumatic cylinder air inlet -   168 pneumatic cylinder air outlet -   170 cover -   180 housing -   200 air source -   220 fluid lubricant -   240 pumping shaft -   250 first air chamber -   260 second air chamber -   270 sensor -   280 sensor -   300 single-line lubrication system -   350 lubricant point -   360 distributor -   370 lubricant outlet -   380 main line -   390 dispenser -   400 dual-line system lubrication system -   410 feed line -   420 feed line -   500 progressive system lubrication system -   510 progressive feeder 

1. A pump assembly for pumping a fluid lubricant such as grease or oil, the pump assembly comprising: a pump mechanism having a fluid lubricant inflow line and a fluid lubricant outflow line, wherein the pump mechanism is configured for moving a fluid lubricant; a pneumatic cylinder having an air inlet and an air outlet, wherein the pneumatic cylinder is configured for being powered by an air source, the pneumatic cylinder comprising a movable member for operating the pump mechanism, the movable member is movable from an upper position to a lower position in an axial direction; a switch for detecting a position of the movable member; a valve configured for shifting a position of the moveable member upon an activation of the valve; and a control unit operable operably connected to the switch and the valve wherein the control unit is configured for controlling the activation of the valve in response to a detection of the position of the movable member by the switch, such that a pumping effect of the pump mechanism can be controlled.
 2. The pump assembly according to claim 1, wherein the pumping effect of the pump mechanism is controlled according to a stroke control mode.
 3. The pump assembly according to claim 1, wherein the pumping effect of the pump mechanism is controlled according to a time delay mode.
 4. The pump assembly according to claim 3, wherein the control unit is capable of delaying the activation of the valve in response to a detection of the position of the movable member by the switch such that the pumping effect of the pump mechanism is time delayed.
 5. The pump assembly according to claim 4, wherein the activation of the valve is delayed by maintaining the movable member at least one of in an upper position and in a lower position.
 6. The pump assembly according to claim 1, wherein the control unit is configured for controlling the activation of the valve in response to external control information.
 7. The pump assembly according to claim 1, wherein the control unit is configured to record various pumping parameters.
 8. The pump assembly according to claim 1, wherein the movable member is operable connected to a pumping shaft of the pump mechanism.
 9. The pump assembly according to claim 1, the pump assembly further comprises a sensor for detecting a flow rate.
 10. The pump assembly according to claim 1, the pump assembly further comprises a sensor for detecting a dosage amount.
 11. The pump assembly according to claim 1, the pneumatic cylinder comprises a first air chamber and a second air chamber.
 12. The pump assembly according to claim 1, wherein the pump mechanism is provided with a suction side and a pressure side, the suction side is connected to the pressure side via a bypass channel.
 13. The pump assembly according to claim 1, wherein the pump mechanism is provided in a form of a barrel pump.
 14. A lubrication system including a pump assembly, the pump assembly comprising: a pump mechanism having a fluid lubricant inflow line and a fluid lubricant outflow line, wherein the pump mechanism is configured for moving a fluid lubricant; a pneumatic cylinder having an air inlet and an air outlet, wherein the pneumatic cylinder is configured for being powered by an air source, the pneumatic cylinder comprising a movable member for operating the pump mechanism, the movable member is movable from an upper position to a lower position in an axial direction; a switch for detecting a position of the movable member; a valve configured for shifting a position of the moveable member upon an activation of the valve; and a control unit operably connected to the switch and the valve, wherein the control unit is configured for controlling the activation of the valve in response to a detection of the position of the movable member by the switch, such that a pumping effect of the pump mechanism can be controlled, wherein the pump assembly is integrated into the lubrication system.
 15. A lubrication system according to claim 14, wherein the lubrication system further comprising a dispenser, wherein the dispenser is operably connected to the pump assembly.
 16. The pump assembly according to claim 1, wherein the control unit is configured to record various pumping parameters including at least one of: flow rate information, dosage amount information and suction level setting. 